UL 971
Standard for Nonmetallic Underground Piping For Flammable Liquids

DETAILS
Edition Number:1SCC Approved:--
Edition Date:1995-10-30DOD Approved: --
Price Code:AANSI Approved: --
Type:ulstd

  • SCOPE

    1 Scope

    1.1 These requirements cover primary carrier, secondary containment, integral primary/secondary containment, normal vent and vapor recovery, nonmetallic pipe, fittings, and systems (products) intended for use underground in the distribution of petroleum-base flammable and combustible liquids, alcohols, and alcohol-blended fuels as identified in this standard.


    1.1 revised effective July 1, 2005

    1.2 The piping covered by these requirements is intended to be installed and used in accordance with the Flammable and Combustible Liquids Code, NFPA 30 and the Standard for Automotive and Marine Service Station Code, NFPA 30A.

    1.3 These requirements cover nonmetallic thermoplastic (flexible) and thermoset (rigid) plastic piping with manufacturer-supplied fittings for underground use only. The products covered by this standard have been evaluated for assembly in normal soil applications by qualified persons in accordance with the manufacturer’s instructions.


    1.3 revised effective July 1, 2004

    1.3.1 The products covered by this standard have not been evaluated for applications in sumps [more than 12 inches (30.5 cm) from sump wall], as connector pipe (between underground pipe and dispensing device), aboveground or marine use, or other applications exceeding ambient temperatures of 75°F (23°C).


    1.3.1 added effective July 1, 2005

    1.4 A product that contains features, characteristics, components, materials, or systems new or different from those covered by the requirements in this standard, and that involves a risk of fire or of electric shock or injury to persons shall be evaluated using appropriate additional component and end-product requirements to maintain the level of safety as originally anticipated by the intent of this standard. A product whose features, characteristics, components, materials, or systems conflict with specific requirements or provisions of this standard does not comply with this standard. Revision of requirements shall be proposed and adopted in conformance with the methods employed for development, revision, and implementation of this standard.

    1 Scope

    1.1 These requirements cover primary carrier and secondary containment nonmetallic pipe and fittings (piping) intended for use underground in the distribution of petroleum-base flammable and combustible liquids, alcohols, and alcohol-blended fuels. Unless otherwise stated, requirements apply to both primary carrier and secondary containment pipe and fittings.

    1.3 In applying these requirements to flexible piping, a separate examination and unique tests are needed to determine whether the piping is appropriate for that purpose.

  • TABLE OF CONTENTS
    Expand All

    • Cover
    • Transmittal
    • Table of Contents
    • UL Foreword
      • Body
        • INTRODUCTION
          • 1 Scope
          • 2 General
            • 2.1 Units of measurement
            • 2.2 Undated references
            • 2.3 Glossary
        • CONSTRUCTION
          • 2A General
        • PERFORMANCE
          • 3 General
          • 4 Cyclic Pressure Test – Primary Piping
          • 4A Short Term Pressure Tests
            • 4A.1 General
            • 4A.2 Leakage test
            • 4A.3 Hydrostatic test
            • 4A.4 Breakdown test
          • 5 Leakage Test – Primary and Secondary Containment Piping
          • 5A Long Term Pressure Tests
            • 5A.1 General
            • 5A.2 Sustained pressure test
            • 5A.3 Cyclic pressure test
          • 6 Hydrostatic Pressure Strength Test – Primary Piping
          • 6A Vacuum Tests
            • 6A.1 General
            • 6A.2 Static vacuum test
            • 6A.3 Cyclic vacuum test
          • 7 Fitting Torque Test
          • 8 Fitting Bending Test
          • 9 Pipe Bending Test
          • 10 Drop Test
          • 11 Drop Test After Conditioning
          • 12 Ball Impact Test
          • 13 Ball Impact Test After Conditioning
          • 14 Crush-Strength Test – Primary and Secondary Containment Piping
          • 14A Pipe Burial Tests
            • 14A.1 General
            • 14A.2 Pull strength test
            • 14A.3 Puncture resistance test
            • 14A.4 Crush resistance test
          • 15 Immersion Tests – Primary and Secondary Containment Piping
          • 15A Long Term Compatibility Test
          • 16 Air-Oven-Aging Test – Primary and Secondary Containment Piping
          • 16A Interstitial Communication Test
          • 16B UV Compatibility Test
          • 16C Nonmetallic Fitting Stress Crack Test
          • 16D Metallic Fitting Stress Crack Test
          • 17 Permeation Test
        • MANUFACTURING AND PRODUCTION TESTS
          • 18 General
          • 19 Leakage Test
        • MARKING
          • 20 General
        • INSTRUCTIONS
          • 21 General
    • Superseded List